Worst air pollution Catedral de Santiago de Compostela - Santiago de Compostela, today and tomorrow

On 19 July 2026, overall air quality in Catedral de Santiago de Compostela is fair. AQI is the main air quality indicator at 40.0/100. Pollution peaks around 6:00 PM (O3: 40.0/100).

On 20 July 2026, air quality conditions in Catedral de Santiago de Compostela will be better than today, with AQI forecast at medium at 45.4/100. Pollution peaks around 7:00 PM (O3: 45.4/100).

When is air quality typically worst in Catedral de Santiago de Compostela? Air quality often reaches its yearly low in the depths of winter, when still, cold air holds local emissions from traffic and heating close to ground level. Spring often marks a turning point, with increasing storminess and rainfall helping to clear accumulated exhaust and smoke from the air. The long, hot days of summer favour ozone build-up, which can spike on the stillest, sunniest afternoons. Early autumn can still bring warm, stagnant spells before the season's returning rain and wind begin clearing the air. This region's wetter, windier Atlantic climate generally keeps annual air quality more consistent than in Spain's drier interior and south.

It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.

Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.

During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.